INTRODUCTORY ESSAY. 43 



flowed with great powers of migratioiij and that they have been 

 aided in their dispersion primai-ily by those changes of climate, 

 land, and sea, which accompany, or are effected by what are 

 called geological changes, and secondarily by the elements and 

 the animal creation. Under these convictions, we feel it im- 

 perative, on philosophical grounds as well as on those of expe- 

 diency, to use every effort to reduce the vast bulk of forms we 

 have to deal with in the Indian Flora to as few species as we 

 can, consistently with a careful study of the structural and 

 morphological characters of each. We shall, as a rule, banish 

 from our minds the idea that a species is probably new be- 

 cause hitherto unknown to ourselves or to the Flora of India ; 

 we shall, upon principle, keep two or more doubtful species 

 as one, carefully and prominently indicating their differences, 

 and, when expedient, ranking them as varieties ; in preference 

 to keeping doubtful species separate till they shall be proved 

 the same ; having ample proof that in so doing we shaU. avoid 

 the greater evil. We shall not think it desirable to adopt the 

 opinions of others in preference to our own* on points where 

 we have had the best materials to judge from. With regard 

 to nomenclature, we shall not alter names established by 

 Linnaeus, and usually retained by subsequent botanical au- 

 thors, upon the ground of their having received prior names 

 before botany was systematized. We shall incline to adopt 

 old established familiar names, though of doubtful applica- 

 bility, in preference to giving new, even when legitimate to 

 do so. We shall endeavour to retain the first published spe- 

 cific namef of a plant, even when the genus requires to be 

 changed, and shall always give preference to priority of pub- 



* This may to some non-botanical readers sound dogmatical, if not presump- 

 tuous ; but the fact is, that a system is deeply rooted and widely spread, of keeping 

 up tnown bad species in so-called deference to authorities ; in nine cases out of . 

 ten, this is done to save the trouble of a re-examination, and in too many, simply 

 to swell catalogues. The same authorities are held very cheap, when they 

 unite what hair-sphtters wish to keep separate. Witness the state of the Bri 

 tish Flora with regard to Willows, Brambles, and Eoses. 



t With eveiy wish to bmd oiu-sclvos by the canons (most of wliich are ex- 



